scholarly journals Damage Identification of High-speed Maglev Guideway Girder Based on Modal Identification

2021 ◽  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Health Monitoring ◽  
High Speed ◽  
Damage Identification ◽  
Element Model ◽  
High Tech ◽  
Maglev Train ◽  
Identification Method ◽  
The Finite Element Model

Abstract. As a modern high-tech rail vehicle, the maglev train realizes the non-contact suspension and guidance between the train and the guideway, which greatly reduces the resistance of the system. Due to the high-speed operation characteristics of maglev trains, the structural health monitoring of guideway girders is particularly important for the safety and stability of maglev train operation. This paper takes the maglev train guideway girder as the monitoring target, and the finite element model of the maglev vehicle-guideway is established to simulate the running state of the train passing through the guideway girder. The dynamic response data of the guideway girder is obtained in the finite element model, considering healthy states and different damage states of the guideway girder. Then, a modal-based damage identification method is proposed, which obtains the guideway girder damage sensitive characteristics by decomposing the guideway girder acceleration response signal. Finally, based on the measured guideway girder acceleration data, this paper verifies the effectiveness of the damage identification method in guideway girder structure health monitoring, which provides reference and guidance for the future maintenance of the maglev guideway girder.

scholarly journals Statistical damage identification method based on dynamic response sensitivity

2018 ◽  
Vol 39 (3) ◽  
pp. 560-571 ◽  
Author(s):  
Ling Mao ◽  
Shun Weng ◽  
Shu-Jin Li ◽  
Hong-Ping Zhu ◽  
Yan-Hua Sun
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Damage Identification ◽  
Element Model ◽  
Measured Data ◽  
Response Sensitivity ◽  
Identification Method ◽  
The Finite Element Model ◽  
Statistical Damage

The traditional deterministic damage detection method is based on the assumption that the measured data and the finite element model are accurate. However, in real situation, there are many uncertainties in the damage identification procedure such as the errors of the finite element model and the measurement noise. Since the uncertainties inevitably exist in the finite element models and measured data, the statistic method which considers the uncertainty has wide practical application. This paper proposes a statistical damage identification method based on dynamic response sensitivity in state-space domain. Considering the noise of the finite element model and measured acceleration response, the statistical variations of the damaged finite element model are derived with perturbation method which is based on a Taylor series expansion of the response vector and verified by Monte Carlo technique. Afterward, the probability of damage existence for each structural element is estimated using the statistical characteristic of the identified structural parameters. A numerical simply supported beam under the moving load is applied to demonstrate the accuracy and efficiency of the proposed statistical method.

Structural damage identification via physics-guided machine learning: a methodology integrating pattern recognition with finite element model updating

2020 ◽  
pp. 147592172092748 ◽  
Author(s):  
Zhiming Zhang ◽  
Chao Sun
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Finite Element ◽  
Finite Element Model ◽  
Health Monitoring ◽  
Damage Identification ◽  
Model Updating ◽  
Element Model ◽  
Data Driven ◽  
Finite Element Model Updating

Structural health monitoring methods are broadly classified into two categories: data-driven methods via statistical pattern recognition and physics-based methods through finite elementmodel updating. Data-driven structural health monitoring faces the challenge of data insufficiency that renders the learned model limited in identifying damage scenarios that are not contained in the training data. Model-based methods are susceptible to modeling error due to model idealizations and simplifications that make the finite element model updating results deviate from the truth. This study attempts to combine the merits of data-driven and physics-based structural health monitoring methods via physics-guided machine learning, expecting that the damage identification performance can be improved. Physics-guided machine learning uses observed feature data with correct labels as well as the physical model output of unlabeled instances. In this study, physics-guided machine learning is realized with a physics-guided neural network. The original modal-property based features are extended with the damage identification result of finite element model updating. A physics-based loss function is designed to evaluate the discrepancy between the neural network model output and that of finite element model updating. With the guidance from the scientific knowledge contained in finite element model updating, the learned neural network model has the potential to improve the generality and scientific consistency of the damage detection results. The proposed methodology is validated by a numerical case study on a steel pedestrian bridge model and an experimental study on a three-story building model.

Modal Analysis of BT Spindle-Toolholder Interface Based on Abaqus/Standard

2013 ◽  
Vol 662 ◽  
pp. 632-636
Author(s):  
Yong Sheng Zhao ◽  
Jing Yang ◽  
Xiao Lei Song ◽  
Zi Jun Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Element Model ◽  
Contact Theory ◽  
High Speed Machining ◽  
The Finite Element Model

The quality of high speed machining is directly related to dynamic characteristics of spindle-toolholder interface. The paper established normal and tangential interactions of BT spindle-toolholder interface based on finite element contact theory, and analysed free modal in Abaqus/Standard. Then the result was compared with the experimental modal analysis. It shows that the finite element model is effective and could be applied in the future dynamic study of high-speed spindle system.

An efficient technique for extraction of nonlinear dynamic features in a model-based feature extraction scheme for machine learning–based structural health monitoring

2020 ◽  
pp. 107754632093374
Author(s):  
Mehdi Fathalizadeh Najib ◽  
Ali Salehzadeh Nobari
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Identification ◽  
Element Model ◽  
Model Based ◽  
Damage Indicators ◽  
Input Model ◽  
Harmonic Components ◽  
Nonlinear Autoregressive ◽  
The Finite Element Model

Super-harmonic components in response to the harmonic excitation are sensitive indicators of damages such as breathing cracks in beams or kissing bonds in adhesive joints. In a model-based damage identification process using pattern recognition, these damage indicators can be extracted from the finite element model for all probable damage cases using stepped-sine simulation that necessitates nonlinear transient dynamic analysis with high computational costs. In this study, a procedure based on nonlinear autoregressive with exogenous input model is introduced as an alternative shortcut method for extraction of the damage indicators. As a case study, the finite element model of a beam connected to a rigid support via a flexible adhesive layer was used to investigate the efficiency of the proposed method. Kissing bond was introduced to the model as the source of nonlinearity via contact elements. The results prove that the super-harmonic components of orders up to 3, extracted from the nonlinear autoregressive with exogenous input model, agreed well with those extracted directly from the finite element model, whereas the computational time is reduced by a factor of 1/5. Consequently, the proposed method is very advantageous in the stage of damage pattern database creation in a real-world model-based damage identification process based on pattern recognition.

scholarly journals Experiment and Analysis of Cord Stress on High-Speed Radial Tire Standing Waves

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Peng-Fei Sun ◽  
Hong-Wu Huang ◽  
Shui-Ting Zhou ◽  
Yi-Jui Chiu ◽  
Meng Du ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Standing Waves ◽  
Element Model ◽  
Experimental Results ◽  
Radial Tire ◽  
Oblique Wave ◽  
Vehicle Velocity ◽  
The Finite Element Model

This paper elaborates on the production mechanisms of standing waves during high-speed tire rolling and analyzes the relationship between the change of wavelength of sidewall waves and the vehicle velocity, from an oblique wave point of view. A finite element model for a 195/65R15 radial tire is established with the nonlinear analysis software ABAQUS, based on the tire structure and cord parameters. This paper comparatively analyzes the finite element simulation results and experimental results of the tire load-sinkage relation and the load vs inflatable section width relation and finds little difference between the simulation and experimental results. A similar analysis studies the change in the wavelength of sidewall standing waves at different vehicle velocities during high-speed tire rolling. The calculated value by the oblique wave approach, the value by simulation, and the experimental results demonstrate high consistency, concluding that during high-speed tire rolling, the wavelength of sidewall standing waves increases with vehicle velocity. Thus, the accuracy of the finite element model is verified under both static and dynamic conditions. Under a constant tire pressure and load, the impact of velocity change on tire-cord stress during high-speed tire rolling is studied based on the finite element model so as to identity the relation between the cord stress and standing waves.

Accurate FEM of Steel-Concrete Composite Box Girder Bridge for Damage Identification Based on Dynamical Experimental Study

2013 ◽  
Vol 330 ◽  
pp. 872-877
Author(s):  
Yi Qiang Xiang ◽  
Li Si Liu ◽  
Shao Jun Li
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Finite Element Model ◽  
Damage Identification ◽  
Element Model ◽  
Scale Model ◽  
Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
The Finite Element Model

Based on the results of experiment, this paper discusses about the updating and validation of accurate finite element model for damage identification of the steel-concrete composite box girder bridge. Taking a 5 meters long steel-concrete composite box girder bridge as the research object and the finite element model is established. By means of scale model test the updating of the accurate finite element model has been completed and validation is confirmed.

A Hybrid 2.5D High Speed Strip Theory Method and its Application to Apply Pressure Loads to 3D Full Ship Finite Element Models

2014 ◽  
Author(s):  
Chengbi Zhao ◽  
Ming Ma
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Hybrid Approach ◽  
Structural Models ◽  
Element Model ◽  
3D Finite Element ◽  
Hull Girder ◽  
Strip Theory ◽  
The Finite Element Model

As the three-dimensional finite element model has become the de facto standard for ship structural design, interest in accurately transferring seakeeping loads to panel based structural models has increased dramatically in recent years. In today’s design practices, panel based hydrodynamic analyses are often used for mapping seakeeping loads to 3D FEM structural models. However, 3D panel based hydrodynamic analyses are computationally expensive. For monohull ships, methods based on strip theories have been successfully used in the industry for many years. They are computationally efficient, and provide good predictions for motions and hull girder loads. However, many strip theory methods provide only hull girder sectional forces and moments, such as vertical bending moment and vertical shear force, which are difficult to apply to 3D finite element structural models. Previously, the authors have proposed a hybrid strip theory method to transfer 2D strip theory based seakeeping loads to 3D finite element models. In the hybrid approach, the velocity potentials of strip sections are first calculated based on the ordinary 2D strip theories. The velocity potentials of a finite element panel are obtained from the interpolation of the velocity potentials of the strip sections. The panel pressures are then computed based on Bernoulli’s equation. Integration of the pressure over the finite element model wetted panels yields the hydrodynamic forces and moments. The equations of motion are then formulated based on the finite element model. The method not only produces excellent ship motion results, but also results in a perfectly balanced structural model. In this paper, the hybrid approach is extended to the 2.5D high speed strip theory. The simple Rankine source function is used to compute velocity potentials. The original linearized free surface condition, where the forward speed term is not ignored, is used to formulate boundary integral equations. A model based on the Series-64 hull form was used for validating the proposed hybrid method. The motion RAOs are in good agreement with VERES’s 2.5D strip theory and with experimental results. Finally, an example is provided for transferring seakeeping loads obtained by the 2.5D hybrid strip theory to a 3D finite element model.

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